Tracking Moulting Patterns in Atlantic puffins (Fratercula arctica): A Seven-Year Study at Oceanário de Lisboa

Moulting is a crucial yet challenging life-history trait to study in seabirds, particularly in the wild. Public aquariums offer valuable opportunities to collect detailed data, which, although not directly transferable to wild populations, provide important insights. At Oceanário de Lisboa, six Fratercula arctica individuals were monitored over seven years to document moulting patterns. The start and end of each moult were consistently recorded around the spring and autumn equinoxes. Pre-alternate moults lasted between 17 and 73 days, while pre-basic moults ranged from 11 to 48 days, with primary moults occurring between the two. This study is the first to document an asynchrony between the primary and the pre-alternate moults in F. arctica, highlighting a previously unreported aspect of the species’ moulting process. This seven-year time series and its findings prompt a call for action for further studies in controlled conditions, to investigate this pattern under different conditions and across puffins’ life stages. Such data could be crucial for developing more effective conservation strategies for this vulnerable species. These findings emphasize the importance of continued monitoring and research on ex situ puffin populations to expand our understanding of their moulting behaviour and its implications for wild populations.